Reinforcement elements for concrete structures

ABSTRACT

A unitary reinforcing mat for reinforcing the top portion of a self-supporting, substantially horizontal concrete slab which includes a plurality of elongated, longitudinally-extending reinforcing bars arranged in spaced, parallel relation to one another and having their free ends bent downwardly to form support legs which are substantially shorter than the remaining longitudinal portion of the bars; at least two connecting bars extending transversely across the longitudinal bars and fixedly attached thereto at points spaced from the tips of the support legs but immediately adjacent the bends in the longitudinal bars so as to rigidly support the support legs and plastic coverings on the tips of the support legs to prevent rusting of any exposed portion thereof. The mats may be formed as a plurality of joined, single longitudinal bars or as pairs of parallel, longitudinal bars and such pairs and multiple single units may be combined with their longitudinal portions parallel to one another or transversely crossing one another.

[ 51 Sept. 26, 1972 United States Patent Bjerking [54] REINFORCEMENT ELEMENTS FOR 3,245,191 4/1966 Ernst...........................52/686 CONCRETE STRUCTURES 3,283,458 11/1966 Gersovitz.....................52/664 [72] Inventor: SvemErik Bjerking, Gotagatan 3, 3,302,360 2/1967 Bjerking......................52/687 pp Sweden FOREIGN PATENTS 0R APPLICATIONS Nov. 8, 1968 ,l48,369 5/1963 Germany.....................52/687 [22] Filed:

211 Appl. No.2 774,539

Primary Examiner-Francis K. Zugel Attorney-Moore and Hall Related US. Application Data P o D. D. 0 t e h t g .m C r m T C r A r m m S m B m A g .m C r m .m e r V. r a an l n 7 U 5 A I 500 ya um m .m I 3 77.0% Am 5u m m 0 c. C d m S ,7 d4 me4 2 0 n 3 .mn a a U 0 .m N 6 m% r. c C S l. 3 6

tion of a self-supporting, substantially horizontal concrete slab which includes a plurality of elongated,

extending reinforcing bars arranged in parallel relation to one another and having their free ends bent downwardly to form support legs I e m .m d

m l s 5 6 5 3 6 4 m n m y uh" r .m fin um .mw t 3 .m m

5 A6 9 .w m 0 EV O N which are substantially shorter than the remaining lonjacent the bends in the longitudinal bars so as to rigidly support the support legs and plastic coverings [56] References Cited UNITED STATES PATENTS on the tips of the support legs to prevent rusting of any exposed portion thereof. The mats may be formed as a plurality of joined, single longitudinal bars or as pairs of parallel, longitudinal bars and such pairs and Ellinger.......................52/652 multiple single units may be combined with their loni gitudinal portions parallel to one another or transver- WhIte..........,...............52/687 sely crossing one another Schuster.....................,52/261 Michalak.....................52/686 6 Claims, 8 Drawing Figures REINFORCEMENT ELEMENTS FOR CONCRETE STRUCTURES This application is a continuation of application Ser. No. 565,423, filed July 15, 1966, now abandoned, and a continuation-in-part of application Ser. No. 332,447 filed Dec. 23, 1963 now US. Pat. No. 3,302,360.

This invention relates to an element for reinforcing the top of substantially horizontally extending self-supporting concrete structures.

I have proposed previously, in copending application Ser. No. 332,447, which issued as US. Pat. No. 3,302,360 on Feb. 7, 1967, of which the present application is a continuation-in-part, to use for the reinforcement of the top of concrete slabs and the like, a reinforcing element consisting of a reinforcement bar bent to the shape of a substantially rectangular elongated loop which is bent over at its ends to form feet for supporting the element on the bottom reinforcement or on low supports or spacers placed on the bottom of the mould. The use of such reinforcement loops entails essential advantages, such as reduced steel weight due to the elimination of the need for separate mounting steels, improved anchoring of the ends of the statically active steel bar portions, and a better protection for the workmen particularly through the absence of the freely extending sharp steel bar ends so characteristic for traditional top reinforcements.

It is an object of the present invention to provide an element for the reinforcement of the top of self-supporting concrete slabs or the like which can be placed directly on the bottom of the mould. With this object in view there has been provided according to the invention a reinforcement element which is characterized substantially therein that it comprises two or more reinforcement bars extending longitudinally substantially in parallel with one another and at suitable mutual distances, and at least two transversely extending reinforcement bars which cross the longitudinally extending bars at a certain distance from the ends thereof and are welded to the longitudinally extending bars at the crossing points so that a rigid unit is obtained, at least some of the longitudinally extending reinforcement bars in said unit being bent through a suitable angle at one or both ends to form freely depending legs or feet for supporting the reinforcement element directly on the bottom of the mould with the straight portions of the longitudinally extending reinforcement bars at the correct distance above the mould bottom. I

Due to the fact that in the reinforcement element according to the invention the mounting feet are formed by freely extending ends of individual reinforcement bars forming part of the element, the element may be supported on the bottom of the mould without interference with the bottom reinforcement or with installations possibly placed on the mould bottom, such as pipes, conduits and the like, ensuring more correct measurements in a vertical direction than when using the previously proposed reinforcement loops. Furthermore, the reinforcement element according to the present invention may to advantage be made in greater units, involving a reduced need for lashing and a consequent saving in the time required for placing the reinforcement in position. In addition, a still more improved anchoring of the ends of the reinforcement bars is obtained.

The invention will now be described more in detail with reference to the accompanying drawings, in which:

FIG. 1 illustrates a first embodiment of a reinforcement element according to the invention placed in position on the bottom of a mould.

FIGS. 2 to 8 show other embodiments of the reinforcement elements.

In FIG. 1, reference numeral 10 designates the bottom of a mould, 11 the bottom reinforcement, and 12 supports or spacers for the latter placed on the mould bottom. The top reinforcement consists of a rigid reinforcement element composed of a plurality of substantially parallel reinforcement bars 14 extending longitudinally substantially in parallel with each other at suitable mutual distances, and of two transversely extending reinforcement bars 15 which cross the longitudinal bars a certain distance from the free ends thereof, the transversely extending bars being welded to the longitudinally extending bars at the crossing points of the bars. At a point positioned a certain distance inside the respective transversely extending reinforcement bars 15, the longitudinally extending reinforcement bars 14 are bent down to form legs 16 the free ends 17 of which serve as feet for supporting the reinforcement element directly on the mould bottom 10 with the straight portions of the reinforcement bars at the desired distance above the mould bottom. Since the free ends 17 of the bars do not become entirely embedded in the concrete, the ends are anti-rust treated in a suitable manner, for example are covered each by a tightly fitting cap of plastic. The reference numeral 18 designates installations in the form of pipes, conduits and the like placed on the mould bottom. It should be immediately clear from the Figure that the shaping of the feet for the reinforcement element as bent-down free ends of longitudinally extending reinforcement bars forming part of the element renders it possible to place the reinforcement element directly on the bottom of the mould without interference with the bottom reinforcement or with possible installation placed on the mould bottom.

In the embodiment according to FIG. 2, which is most like the previously proposed reinforcement loop, the reinforcement element has only two reinforcement bars 14 extending longitudinally in parallel at suitable distance, the said longitudinally extending bars being held together by two transversely extending reinforcement bars 15 so that a rigid unit 19 is formed.

The reinforcement element according to FIG. 3 consists of a plurality of rigid reinforcement units 19 according to FIG. 4 and two transversely extending reinforcement bars 20 which are welded to the straight portions of the longitudinally extending bars to form a reinforcement mat in which the individual reinforcement units are displaced longitudinally with respect to each other. Since the reinforcement bars 20, which serve to hold together the units 19 to form a mat, cross every second reinforcement unit 19 close to a leg or foot portion, the said reinforcement bars will constitute supports for the intermediate reinforcement units in which the foot portion is positioned at a comparatively large distance from the reinforcement bar 20.

The reinforcement element according to FIG. 4 consists, similarly to the element according to FIG. 1, of a plurality of reinforcement bars 14 which are bent over at the ends and are held together by transversely extending reinforcement bars 20 welded to the longitudinally extending bars to form a reinforcement mat. In this embodiment the longitudinally extending bars 14 are displaced with respect to each other in the longitudinal direction, and the transversely extending reinforcement bars 20 cross the straight portions of the longitudinally extending bars. Since the reinforcement bars 20. cross every second of the longitudinally extending bars 14 close to the bent down portion, the reinforcement bar 20 will constitute a support for the intermediate reinforcement bars 14 in a manner similar to the embodiment according to FIG. 3.

The reinforcement elementaccording to FIG. 5 consists of a plurality o reinforcement bars 14 which are bent down at their ends and are held together to form a rigid unit with the aid oftwo transversely extending reinforcement bars 20, the latter bars crossing the straight portions of the longitudinally extending bars close to the bent-down ends. The rigid unit thus formed constitutes a support for a plurality of rigid units 19 according to FIG. 2 welded or lashed to the transversely extending reinforcement bars 20.

The reinforcement element according to FIG. 6 is a combination of a reinforcement element 21' according to FIG. 1 and a plurality of reinforcement units 19 according to FIG. 2, the longitudinally extending reinforcement bars of the respective reinforcement elements and units extending in parallel with each other.

The reinforcement element according to FIG. 7 consists of two reinforcementunitsl9 according to FIG. 2 which cross each other under a straight angle.

The reinforcement element according to FIG. 8 is a combination of two reinforcement elements 21 according to FIG. 1, the longitudinally extending reinforcement bars of the respective reinforcement elements being positioned cross-wise with respect to each other.

Many other embodiments are conceivable without departing from the scope of the invention.

What is claimed is:

l. A unitary reinforcing mat for reinforcing the top portion of a self-supporting, substantially horizontal concrete slab formed in a mold, comprising:

a. at least four elongated, generally horizontallydisposed' reinforcing bars arranged in spaced, parallel relation to one another and arranged in pairs of two to form at least two pair units;

b. said reinforcing bars of said pair units having both free ends thereof bent downwardly to form generally vertically-disposed support legs substantially shorter than the remaining horizontal portion of said reinforcing bars and making point contact with the bottom surface of said mold;

c. one end of at least one of said pair units being offf. the major portion of said horizontal portion of said reinforcing bars being free of transverse bars and said horizontal portions of said reinforcing bars forming the sole upper support for said slab.

2. A unitary reinforcing mat for reinforcing the top portion of a self-supporting, substantially-horizontal concrete slab formed in a mold, comprising:

a. a pair of elongated, generally horizontallydisposed reinforcing bars arranged in spaced, parallel relation to one another;

. said reinforcing bars having their'free ends bent downwardly to form generally vertically-disposed support legs substantially shorter than the remaining horizontal portion of said bars and making point contact with the bottom surface of said mold;

c. a connecting bar adjacent each end of said reinforcing bars, extending transversely across said reinforcing bars and welded thereto to form a pair unit;

d. said connecting bars being attached to said reinforcing bars immediately adjacent the bend thereof and spaced from the tips of said bent down free ends of said reinforcing bars;

e. a plurality of said pair units being'arranged in spaced, parallel relation to one another;

f. at least two additional connectingrods extending transversely across said remaining horizontal portions of said pair units a substantial distance from the ends of said pair units and welded thereto; and

g. additional reinforcing bars welded to said additional connecting bars and having both free ends bent downwardly immediately adjacenttheir connection to said additional connecting bars to form support legs of substantially the same length as the support legs of said pair units;

h. said remaining horizontal portions of said reinforcing bars forming the sole upper support for said slab. v

3. A-mat in accordance with claim 2 wherein the additional reinforcing bars are spaced between adjacent ones of the pair units. 4

4. A mat in accordance with claim 2 wherein the additional reinforcing bars areadjacent the horizontal portions of the pair units.

5. A unitary reinforcing mat for reinforcing the top portion of a self-supporting, substantially-horizontal concrete slab formed in a mold, comprising:

a. a pair of elongated, generally horizontallydisposed reinforcing bars arranged in spaced, parallel relation to one another;

b. said reinforcing bars having their free ends bent downwardly to form generally vertically-disposed support legs substantially shorter than the remaining'horizontal portion of said bars and making point contact with the bottom surface of said mold;

c. a connecting bar adjacent each end of said reinforcing bars, extending transversely across said reinforcing bars and welded thereto to form a pair unit;

d. said connecting bars being attached to said reinforcing bars I immediately adjacent the bend thereof and spaced from the tips of said bent down free ends of said reinforcing bars;

e. a plurality of said pair units being arranged in spaced, parallel relation to one another to form a first unit;

. still another unit formed in the same manner as said pair unit by more than two reinforcing rods having shorter horizontal portions than said pair units and a finished width substantially equal to the overall width of said first unit;

. said other unit and said first unit being fixedly attached to one another with said remaining horizontal portions of said other unit parallel to said remaining horizontal portions of said first unit;

. said remaining horizontal portions of said reinforcing bars forming the sole upper support for said slab.

. at least one connecting bar extending transversely across the reinforcing bars having their ends bent downwardly, immediately adjacent the bent down portion of said reinforcing bars and spaced from the tips of said bent down free ends of said reinforcing bars, and welded thereto;

. at least one of said reinforcing bars having one end offset from one end of at least one other reinforcing bar;

. the major portion of said horizontal portion of said reinforcing bars being free of transverse bars and said horizontal portions of said reinforcing bars 6. A unitary reinforcing mat for reinforcing the top portion of a self-supporting, substantially horizontal forming the PP Support for Sam slab; and concrete slab formed in a mold, comprising; f. at least two units, formed as above, are arranged at least two elongated generally horizonta1|y with their horizontal portions transverse to one disposed reinforcing bars arranged in spaced, parallel relation to one another;

b, at least two of said bars having both of their free another and fixedly attached to one another where said horizontal portions cross one another. 

1. A unitary reinforcing mat for reinforcing the top portion of a self-supporting, substantially horizontal concrete slab formed in a mold, comprising: a. at least four elongated, generally horizontally-disposed reinforcing bars arranged in spaced, parallel relation to one another and arranged in pairs of two to form at least two pair units; b. said reinforcing bars of said pair units having both free ends thereof bent downwardly to form generally verticallydisposed support legs substantially shorter than the remaining horizontal portion of said reinforcing bars and making point contact with the bottom surface of said mold; c. one end of at least one of said pair units being offset from one end of at least one other pair unit; d. at least one connecting bar extending transversely across each of the reinforcing bars having their ends bent downwardly, immediately adjacent the bent down portion of said reinforcing bars and spaced from the tips of said bent down free ends of said reinforcing bars, and welded thereto; and e. additional connecting bars extending transversely across the remaining horizontal portions of said pairs units and fixedly attached thereto; f. the major portion of said hoRizontal portion of said reinforcing bars being free of transverse bars and said horizontal portions of said reinforcing bars forming the sole upper support for said slab.
 2. A unitary reinforcing mat for reinforcing the top portion of a self-supporting, substantially-horizontal concrete slab formed in a mold, comprising: a. a pair of elongated, generally horizontally-disposed reinforcing bars arranged in spaced, parallel relation to one another; b. said reinforcing bars having their free ends bent downwardly to form generally vertically-disposed support legs substantially shorter than the remaining horizontal portion of said bars and making point contact with the bottom surface of said mold; c. a connecting bar adjacent each end of said reinforcing bars, extending transversely across said reinforcing bars and welded thereto to form a pair unit; d. said connecting bars being attached to said reinforcing bars immediately adjacent the bend thereof and spaced from the tips of said bent down free ends of said reinforcing bars; e. a plurality of said pair units being arranged in spaced, parallel relation to one another; f. at least two additional connecting rods extending transversely across said remaining horizontal portions of said pair units a substantial distance from the ends of said pair units and welded thereto; and g. additional reinforcing bars welded to said additional connecting bars and having both free ends bent downwardly immediately adjacent their connection to said additional connecting bars to form support legs of substantially the same length as the support legs of said pair units; h. said remaining horizontal portions of said reinforcing bars forming the sole upper support for said slab.
 3. A mat in accordance with claim 2 wherein the additional reinforcing bars are spaced between adjacent ones of the pair units.
 4. A mat in accordance with claim 2 wherein the additional reinforcing bars are adjacent the horizontal portions of the pair units.
 5. A unitary reinforcing mat for reinforcing the top portion of a self-supporting, substantially-horizontal concrete slab formed in a mold, comprising: a. a pair of elongated, generally horizontally-disposed reinforcing bars arranged in spaced, parallel relation to one another; b. said reinforcing bars having their free ends bent downwardly to form generally vertically-disposed support legs substantially shorter than the remaining horizontal portion of said bars and making point contact with the bottom surface of said mold; c. a connecting bar adjacent each end of said reinforcing bars, extending transversely across said reinforcing bars and welded thereto to form a pair unit; d. said connecting bars being attached to said reinforcing bars immediately adjacent the bend thereof and spaced from the tips of said bent down free ends of said reinforcing bars; e. a plurality of said pair units being arranged in spaced, parallel relation to one another to form a first unit; f. still another unit formed in the same manner as said pair unit by more than two reinforcing rods having shorter horizontal portions than said pair units and a finished width substantially equal to the overall width of said first unit; g. said other unit and said first unit being fixedly attached to one another with said remaining horizontal portions of said other unit parallel to said remaining horizontal portions of said first unit; h. said remaining horizontal portions of said reinforcing bars forming the sole upper support for said slab.
 6. A unitary reinforcing mat for reinforcing the top portion of a self-supporting, substantially horizontal concrete slab formed in a mold, comprising: a. at least two elongated, generally horizontally-disposed reinforcing bars arranged in spaced, parallel relation to one another; b. at least two of said bars having both of their free ends bent downwardly to form generally vertically-disposed support legs substantially shorter than the remaining horizontal portion of said bars and making point contact with the bottom surface of said mold; c. at least one connecting bar extending transversely across the reinforcing bars having their ends bent downwardly, immediately adjacent the bent down portion of said reinforcing bars and spaced from the tips of said bent down free ends of said reinforcing bars, and welded thereto; d. at least one of said reinforcing bars having one end offset from one end of at least one other reinforcing bar; e. the major portion of said horizontal portion of said reinforcing bars being free of transverse bars and said horizontal portions of said reinforcing bars forming the sole upper support for said slab; and f. at least two units, formed as above, are arranged with their horizontal portions transverse to one another and fixedly attached to one another where said horizontal portions cross one another. 